Embodiments relate to an infrared imaging system with an athermalized dual-band ultra-wide field-of-view (WFOV) optical system and method.
Imaging systems that occupy a small volume of space have been designed with optical systems with high F/numbers and smaller focal plane arrays (FPAs). Additionally, these small imaging systems have been designed as monochromatic mid-wave infrared (MWIR) systems. As situational-awareness devices for surveillance become common place, dual-band imaging systems which are also miniaturized are needed.
Infrared detectors include a focal plane array (FPA) being cryogenically cooled in a dewar within an enclosure with a warm optical window. The enclosure however is subject to temperature variations of the surrounding environment which causes expansion and contraction variations or shifting due to the temperature fluctuations. As the enclosure expands and contracts (i.e., shifts) as a function of the temperature variations of the environment, so does the FPA shift. This shift can cause various optical distortions.